Indonesian rescuers are searching for 7 people still missing four days after torrential rain hit North Sumatra province, causing flash flooding and landslides which killed 15 people, an official said on Tuesday.

Torrential rain unleashed flooding and landslides on Indonesia's Sumatra island, killing 20 people and leaving at least two others missing.

Rescue workers in western Indonesia used heavy equipment on Tuesday to dig out from weekend flooding and landslides that have killed at least 20 people, the national disaster agency said.